Abstract:

The aims of the present study were: i) to evaluate the construct validity of Yo-Yo Intermittent Recovery Test Level 2 (Yo-Yo IR2) and of the Margaria Test (MT) with performance in high intensity exercise during official match play in soccer players; ii) to verify the reliability (test-retest) of the two tests; iii) to compare the values of the maximal individual heart rate (MHR) obtained in those protocols and match play Eighteen soccer players (mean ± SD; age 14 ± 0.8 years, height 172 ± 9 cm, weight 64.3 ± 8.5 kg) belonging to the same team were assessed in test-retest referred protocols and in the percentage of time spent above 85% of MHR (PRT >85%MHR) in two official match play of the U-15 Championship. High correlation was found between performance in the Yo-Yo IR2 and PRT >85%MHR (rs=0.71; p<0.05). There was not correlation between performance in MT and PRT >85%MHR (rs=0.44; p=0.06). The Yo-Yo IR2 was more variable and less reproducible (CV= 11%; CCI [95% IC]=0.38) than MT (CV= 1%; CCI [95% IC]=0.93). The highest value of MHR (p<0.001) occurred in the match play (202 ± 8 beats.min-1). MHR in Yo-Yo IR2 (194 ± 4 beats.min-1) was lower (p<0,006) than MT (197 ± 6 beats.min-1). In conclusion, the Yo-Yo IR2 can be considered more valid to predict maintenance of high exercise intensity during a match, which is an important performance measure in soccer. However, there is need of strict standardization among the evaluation procedures for stability of the measure. MHR should be observed in several situations, mainly competitive, so that the highest individual value can be reached.